al-Mughira, known as Abu Lu'lu'a, assassinated Umar while the latter was praying in Medina. Umar's successor, Caliph Uthman (), kept al-Mughira as governor for another year until replacing him with Sa'd ibn Abi Waqqas. Al-Mughira retired from public life and returned to Ta'if upon the accession of Caliph Ali () following Uthman's assassination in 656. From his hometown, he observed the chaotic events of the First Muslim Civil War between the supporters of Ali, who made Kufa his capital, and the bulk of the Quraysh, who opposed Ali's caliphate. When Ali and Mu'awiya ibn Abi Sufyan, the governor of Syria who had taken up the cause of avenging the death of his Umayyad kinsman Uthman, decided to settle the Battle of Siffin by arbitration in 657, al-Mughira, without invitation by either side, attended the talks at Adhruh. Umayyad governor of Kufa During the chaos that ensued in the aftermath of Ali's assassination in 661, al-Mughira apparently forged a letter by Mu'awiya, who had since claimed the caliphate, giving al-Mughira responsibility of leading the annual Hajj pilgrimage to the Ka'aba in Mecca. According to the orientalist Henri Lammens, al-Mughira's "shocking morals", lack of attachment to the Alids (kinsmen and partisans of Ali), non-involvement in the "jealousies of the Quraysh [sic], as well as the narrow-mindedness of the Ansar" (another faction of the Muslim elite), and membership of the "intelligent and enterprising tribe of Thaqif [sic]", all gained the attention of Mu'awiya, who reappointed him governor of Kufa in 661. Al-Mughira was known in the tradition as one of the principal "shrewds" of his era "who could get himself out of the most hopeless difficulty". Indeed, he was able to maintain relatively cordial relations with the influential Alids of Kufa and utilized them to counter their enemies, the Kharijites. The latter were composed of Ali's erstwhile supporters who defected from him as a result of the arbitration with Mu'awiya, assassinated him and continued to rebel against the authorities in Iraq. According to Lammens, "by setting them [Alids and Kharijites] against one another he rendered harmless the most dangerous elements of disorder in his province". Moreover, by "combination of mildness and astuteness, and by knowing when to shut his eyes, al-Mughira succeeded in avoiding desperate measures" against the politically turbulent factions of Iraq and was able to maintain his governorship. Al-Baladhuri mentions in his Genealogies of the Nobles (Arabic: أنساب الأشراف; Ansab al-Ashraf),